testator

When you make your last will and testament, you are the testator, and if the will is written and witnessed according to the law of the land, your estate will be divided in the way you, the testator, requested.

The noun testator comes from the Latin verb testari, meaning “make a will,” “be witness,” or “declare.” Perhaps your aunt, as testator of her will, indicated that she wanted you to inherit her collection of garden statuettes to keep her daughter from “smashing them to bits and heaving them in the dump.”